Multi-Series and Trend Lines
When you add a chart with a Chart Type of Line or Column to your dashboard, there is additional configuration available. You can display up to three Views on the same chart and enable a trend line for each View.
In the View drop-down list, select from any View available to you. For multi-series charts, you must define a View for the first drop-down option. The current View displays as the pre-inserted View unless you select another option. You can also define Views for the second and third drop-down options, or set them to (clear) if you dont' need them. To include All Records, set this in the first drop-down list. You can enable or disable a trend line for each View.